Nutrient cycling in native systems and agroecosystems in well and poorly drained soils

Abstract

Long-term plots (44 yr) under no till (NT) and plow till (PT) and different crop rotations (continuous corn, corn-soybean and corn-oats-hay) in well and poorly drained sites are sampled on a decadal basis to track the changes induced on major soil nutrient dynamics and soil physicochemical properties. A pit sampling was included to ascertain macro and micromorphological changes in the topsoil, considering also woods and grassed areas. Cultivation modified structure development with a strong stable structure found under grass followed by NT and then PT. Bulk density was related to the degree of structure development (or degradation) with the greatest values for PT in the topsoil. The C pool in the topsoil was greater in Wooster under NT than for PT, almost similar for both treatments in Hoytville. Grassed and wooded areas have higher organic C stocks with higher levels in the poorly drained site. Long-term maintenance of NT, compared to PT, led to an accumulation of organic matter and a sustained ability to support high grain yields in the soil with highest susceptibility to erosion (Wooster), suggesting that NT management can sustain or even enhance soil quality in this site.